A pro-Russian rebel looks up while ridding on a tank flying Russia's flag, on a road east of Donetsk on Monday.

VADIM GHIRDA — AP

KIEV, Ukraine — Three Ukrainian border guard brigades were said to be close to eating grass to survive, running out of ammunition and food, trapped on the eastern edge of their country between Russian separatists to their west and fire coming in from Russia to their east.

Its a siege that began July 11 as the troops tried to protect the Ukrainian border with Russia near Zelenopolye. The first night, 23 Ukrainian troops died, 93 were wounded badly, and while theyve managed to evacuate 75 of the wounded and reinforcements arrived Thursday, the struggle on the border points out a single truth of this allegedly internal war in the so-called Donbas region:

If there is to be victory in Ukraines months-old civil war in the southeast, it will begin along the Russian border.

Ukrainian and U.S. officials insist Russia has an established and continuing supply and resupply of weapons and experienced troops and advisers flowing in to help the pro-Russian separatists.

And the United States said Thursday that it had evidence that Russia is launching artillery fire across its border and providing heavier rocket launchers into Ukraine, in what Pentagon officials described as a clear escalation of the conflict.

We have new evidence that the Russians intend to deliver heavier and more powerful multiple rocket launchers to the separatist forces in Ukraine, and have evidence that Russia is firing artillery from within Russia to attack Ukrainian military formations, State Department spokeswoman Marie Harf told reporters at the departments daily briefing.

Ukrainians say the fight against that resupply will have to focus on villages such as Izvarino and Dolzhanskaya and Chervonopartyzansk, places that usually are barely considered but in this conflict are central to any chance of Ukrainian victory.

The network of paved and unpaved roads in and around these border villages forms the backbone of the supply lines from Russia to the pro-Russian separatists. Or, put in an American historical context, these spots are essential to the Ho Chi Minh Trail of the Ukrainian conflict.

Col. Andriy Lysenko, spokesman for the Ukrainian National Security and Defense Council, noted that in this area, the attacks are almost continuous.

He also noted that the fire from Russia creates a dangerous dilemma for the Ukrainian military. The fire puts them in danger, but returning fire would legitimize Russian troops moving into the region openly and in large numbers.

Thus far, the Ukrainians had maintained a delicate balance, Lysenko said. The most noted piece of heavy equipment alleged to have rolled into this conflict from Russia is the Buk anti-aircraft system allegedly used by separatists to take down Malaysia Airlines Flight 17, which resulted in 298 deaths.

But Ukrainian military officials and experts note that the supply of weapons goes far beyond one anti-aircraft system.

Lysenko said the supply of light arms and ammunition being used by the separatists to fight against Ukrainian troops is enormous.

The tanks, armored personnel carriers and anti-aircraft weapons, including Buk and MANPADS, were substantial, he said.

Ukrainian forces had increased shelling on several border crossings, Lysenko said, and had been able to slow the flow of arms, for a few days at least. He said the slowed flow of weapons had an almost immediate impact on the battlefield.

But other military officials disagreed with the notion that the Russian weapons resupply had decreased.

Anton Gerashchenko, when asked Wednesday if the supply lines had been disrupted, pulled out a cellphone showing a steady stream of updates, such as the one noting that around 10 a.m. Ukrainian witnesses saw five new tanks and other equipment crossing the border.

We thought perhaps the tragedy of Flight MH17 would cause them to pause the weapons flow, but that has not been the case, he said.

Oleksiy Melnyk, co-director for security at the Ukrainian think tank Razumkov Centre, said the on-the-ground reality created by the flow of weapons from Russia is that the Russian separatists are better armed than the Ukrainian military.

He added that Ukraine could not hope to stand toe to toe in a proxy war with Russia, and therefore would have to rely on the administration of Russian President Vladimir Putin deciding to stop a policy of aggression in the region.

As if to highlight the gap between the Russian and Ukrainian militaries, in Ukraines parliament, the Rada, on Thursday, legislators were talking about the need to increase military funding, as the $1 billion theyd added to the budget earlier this year to aid in the effort was already almost all gone.

Member of Parliament Sergiy Kunitsyn noted that more money is needed or we will run out of ammunition, food, fuel, everything.

At the Pentagon, a U.S. defense official said that Russian artillery has been fired over the border for days, beginning roughly around the same time MH17, traveling from Amsterdam to Kuala Lumpur, was shot down, killing the 283 passengers and 15 crew on board. Such artillery could not have shot down that plane, which was traveling at 33,000 feet when it was struck.

Why the State Department only announced the Russian escalation into the conflict Thursday was unclear. The announcement, however, was likely to increase international pressure on Russia to cut off its support for the separatists.

The Pentagon offered no specifics on which Russian forces were launching the artillery, their targets or what they have struck.

In the past few weeks, U.S. officials said they have seen various weapons traveling along the border, including lighter Soviet-era armored surface-to-surface rocket launchers. The United States believes Russia plans to deliver BM-30 Smerch, a powerful, heavier multiple-launch rocket system, consisting of 12 tubes for 300mm rockets, to separatists across the border.

U.S. officials estimate there are close to 12,000 Russian troops currently at the border.

There was no indication from Washington that the attacks were related the resignation Thursday of the government of Ukraine Prime Minister Arseniy Yatsenyuk, amid growing optimism among some parts of the government that its military can fend off the pro-Russian insurrection.

Rather, Pentagon officials believe the Russian strikes are designed to provide cover for separatists against an improving Ukrainian army. Ukraine, keen to not further involve Russia in the conflict, has little regress against such cross-border attacks.

The news of the strikes comes just a day after Ukraine said two of its Sukhoi SU-25 fighter jets were struck in the Donetsk region. But there was no indication that Russian artillery was involved in those shootdowns. Flying at 6,000 feet, it would be nearly impossible for artillery to strike down SU-25 fighters jets, but U.S. officials could not rule out the Russian artillery.

Separatists in Ukraine said they used MANPADs _ shoulder-launched surface-to-air missiles _ to bring down those aircraft.

Join The Conversation

McClatchy Washington Bureau is pleased to provide this opportunity to share
information, experiences and observations about what's in the news.
Some of the comments may be reprinted elsewhere in the site or in the
newspaper. We encourage lively, open debate on the issues of the day,
and ask that you refrain from profanity, hate speech, personal
comments and remarks that are off point. Thank you for taking the time
to offer your thoughts.